IL-Iα, IL-Ira and IL-8 are differentially induced by Candida in experimental oral candidiasis

Objective: To investigate the expression of interleukin I alpha (IL-I alpha), IL-Ira and IL-8 by the oral epithelium challenged by various Candida species. Materials and methods: In vitro candidiasis was induced by C. albicans wild type SC5314, its EFGI, CPHI and secretory aspartyl proteinase (SAP) mutants and, ATCC isolates of C. albicans, C. tropicalis and C. dubliniensis using a reconstituted human oral epithelium (RHOE) model. IL-I alpha, IL-Ira and IL-8 levels in culture media were quantified by an enzyme-linked immuno-sorbent assay at 12, 24 and 48 h. Fungal invasion and IL-Ira expression in RHOE were detected by periodic acid-Schiff staining and immunohistochemistry. Results: Overall, the invasive Candida induced relatively higher levels of IL-I alpha, IL-Ira and IL-8 in the culture media than the noninvasive isolates. IL-I alpha and IL-Ira levels induced by Candida with hyphal invasion were significantly higher (P < 0.05) than those induced by the isolates without hyphal invasion at 12, 24 and 48 h. Candida albicans SCS314 induced IL- Ira expression in RHOE at 12 and 24 h but not at 48 h consistent with its hyphal invasion; while the noninvasive mutants and non-albicans Candida induced IL- Ira expression at 48 h. Conclusions: The cytokine expression profiles in experimental oral candidiasis may be associated with the invasive potential of Candida.